Field of the Invention
The present invention relates to a method for fabricating a hard mask on a substrate, and in particular to a method for fabricating a hard mask on a main area of a semiconductor substrate.
Although applicable, in principle, to a wide variety of substrate structures, the present invention and the problems on which it is based will be described using a semiconductor substrate.
Hitherto, only a hard mask layer that has been opened directly using a photolithographically patterned resist mask has been used for etching semiconductor substrates.
This mask can no longer be used to etch semiconductor substrates with an extremely high aspect ratio or to pattern materials that are difficult to etch if the mask requires a hard mask thickness that can no longer be opened at all in a single etching step with a photoresist mask.